BLOG: If we are serious about climate mitigation, we must do smarter ocean nature protection

19 May, 2021 science

This week at Climate Exp0, Dr David Barnes, benthic marine Ecologist at British Antarctic Survey, has discussed the potential for mitigating climate change through nature-based solutions, including sharing collaborative research providing an assessment of Atlantic UK Overseas Territory blue carbon stocks. In the blog below, first published at Climate Exp0, David explores how we can help nature to help us by protecting and restoring key marine habitats.

Nature has a super-power. It happens to be exactly what we need, a massively efficient ability to influence climate through the carbon cycle, addressing the most serious threat to society everywhere. We have been drastically undervaluing nature, and nature-based solutions, especially in the oceans, comprising 70% of our planet. We urgently need to help nature, help us.

If we target protection and rebuild of nature-based solutions in time, these can aid in cooling the planet. We need to protect carbon-rich ecosystems that are still intact and restore damaged ones, especially hotspots where nature most effectively benefits society by fighting climate change. This means working out which habitats, in which places, to prioritise for effective protection; identifying what threats they face; which of these we can tackle; and how best to manage them so that they function optimally.

Reducing greenhouse gas emissions has to be done in tandem with protection and restoration of key habitats and better management of ‘working’ ecosystems. Nature, like the marine environment, is efficient in capturing carbon through photosynthesis, storing it in the body of organisms and ultimately burying it in ocean sediments. As such, conservation is extremely cost effective at helping combat climate change. Yet little of the ocean is protected, and even less so properly.

The UK is hosting COP26 and has set bold targets to reduce the nation’s climate impact by reducing carbon emissions. Identifying key natural carbon sinks, their status, threats and how to best protect and manage them could be a significant help to meet those targets. This could also protect biodiversity and improve quality of life. Where do we look? The majority of UK controlled territorial waters are not around the British Isles but around a network of distant archipelagos from the Caribbean, to remote mid-ocean islands as seen in the map below.

We know little about the ecosystems around these islands. Mangrove swamps, seagrass beds, salt marsh and kelp forests are obvious, important, coastal ‘blue carbon’ (carbon stored in the bodies of organisms) habitats. We can map these through satellites or remote sensing, with some ground-truthing through observers spot checking a few localities. Less obvious is the nature in the other greater area in deeper water.

The mid-Atlantic island of Ascension is small, but rich, cold coral reefs stretching hundreds of meters deep surround it. Surveying 3% of the seabed there showed organisms to store 43,000 tonnes of carbon; the equivalent of 158,000 tonnes of CO2. Nature’s benefits in even this tiny area is worth £1–2 million in what the UN calls the shadow price of carbon.

Even further away in remotest, freezing waters of British Antarctic Territory there are very much larger stores of carbon in nature, a thousand times larger — and actually increasing with climate change, termed as a negative or mitigating feedback.

The UK has protected waters around the overseas territory of South Georgia which has proved a biodiversity and blue carbon hotspot but the UK’s 14 overseas territorial waters are almost certainly custodians of considerable blue carbon sinks. Survey of the deeper habitats around these areas should be an immediate priority.

There are many challenges, not least understanding the complicated interactions between stressors like climate change, fishing, pollution and others on nature. However, increasing awareness and a strong will to halt and reverse nature losses are opening up opportunities for conservation work.

Inevitably, many coastal zones are multi-use, so it is really important to properly consult and involve local people and to make sure they benefit from such conservation. Again, much intact blue carbon habitat is remote and beyond satellite penetration of water depth, so there is a need to get strong assessments done to prioritise protection, meaningful monitoring and threat identification. The new research vessel RRS Sir David Attenborough amongst other UK platforms could be a powerful tool for UK-lead science. Likewise, there is a surge of interest for citizen science project work and to involve schools and universities in shore-based blue carbon surveys.

Nature based solutions, especially in the sea, have received little attention but conservation of mature blue carbon habitats and restoration of damaged ones is very efficient at the whole carbon pathway to genuine sequestration. It can have a strong role in reaching our climate goals alongside emissions reductions and technological solutions.

The need for urgent action is obvious but we must not waste much of that effort on poorly thought out or inefficient attempts at decarbonisation. Nature-based solutions clearly offer potent win-wins, but we need to do the right things, in the right places, right now.

Find out more about David Barnes’ work via the Climate Exp0 media library.

Climate Exp0 is the first virtual conference from the COP26 Universities Network and the Italian University Network for Sustainable Development (RUS), sponsored by UK Research and Innovation (UKRI), Cambridge University Press, the Conference of Italian University Rectors (CRUI), and the 2021 UN Climate Change Summit (COP26).

Running from 17–21 May 2021, it takes place at a critical juncture in the COP26 pre-meetings and negotiations, and is part of the All4Climate Italy 2021 official pre-COP26 initiatives. Learn more and register your place via https://www.climateexp0.org.